I have relevant quotes for these questions, not just mere speculation!
When does Way of Kings take place relative to Mistborn, Elantris, and Warbreaker? It may be that Sazed has been Shardholder for a while, or that Alendi isn't even born yet.
I thought I remembered the books were scattered all over the Overall Timeline. I think Elantris was either very early or late, comparatively.
Though maybe you're right, because now that I think about it, the epigraphs did seem to mention Ati as finished.
This is one of the answers we got in the 17th Shard interview which should* come this weekend. He said all the books have occurred in chronological order in the cosmere as they've been published. So Elantris, Mistborn, Warbreaker, then Way of Kings, in that order.
Also, Will found out at the Chicago signing that Odium went to Sel before the events of Elantris.
Next, for the actual question at hand, here's what I asked him in May:
Q: Will Sazed eventually go mad trying to hold two Shard's power at the same time (being pushed to two different Purposes simultaneously for millennia)? Why hasn't anyone else tried this trick before in the Cosmere?
ANSWER: No. Since they're so opposite they work together to create a whole. However, after a LONG time it would change him as a person.
So... there you have it, I guess?
whats odium? i've read all but way of kings in the adolsuim universe is it something in the way of kings?
Yes, this is probably quite spoilery. I strongly suggest you read it.